For example, the number of transistors mounted on a semiconductor device such as a LSI is nowadays highly integrated up to several tens million pieces in conformity with Moore's law. To mount the highly integrated transistors on a semiconductor chip smaller in size, miniaturization of the transistors and that of wirings and the like for connecting these transistors are being developed. On the other hand, as meltdown of the wirings is made easy according to the miniaturization of the wirings, a voltage of a power source is being made lower. Also, as information processings of the semiconductor devices are performed at high speed, the transistors are operated by high speed switching.
When the transistors are operated by the high speed switching, such a problem becomes pronounced that unstableness of operations of circuits, malfunction of the circuits, and the like occur due to a power source noise which is caused when a high current instantaneously flows in a power source system and when a power source voltage is fluctuated. Hence, for example, a so-called bypass capacitor is provided outside an LSI. By charging/discharging electric charges charged in the bypass capacitor instantaneously when the power source noise occurs, voltage fluctuation of the power source is compensated so as to deal with the power source noise.
Incidentally, the present inventors have made a conventional technique search based on a result of the invention from the viewpoint of the fact that: a first branch line (wiring) and a second branch line (wiring) electrically connected respectively to power sources Vdd and Vss supplied to a core cell are oppositely provided to form a capacitor; and this capacitor reduces the power source noise. As a result, from the viewpoint of the power source noise being reduced, Japanese Patent Application Laid-open Publication No. 2001-85630 (Patent Document 1) has been extracted. This Patent Document 1 discloses that the power source noise is reduced by vertical capacitors formed between through-holes extending in a longitudinal direction vertical to a substrate, but no mention is made of formation of capacitors only by the wiring that extends in a horizontal direction parallel with the substrate.